Cleaning of enclosed vessels is an important task in the chemical industry. In particular reference to the photographic industry, large vessels or kettles are utilized to prepare silver halide emulsions, and these vessels must be cleaned regularly because the inner surfaces of the vessels and baffles and agitators located in the vessels become contaminated and fouled, e.g., as the vessels empty at elevated temperature. If the vessels were not thoroughly cleaned, subsequent batches of silver halide emulsion prepared therein would be contaminated and useless for photographic purposes.
Cleaning of the vessel interiors has heretofore been accomplished by manually scraping the interior walls, baffles and agitator blades. Manual methods are time consuming and expensive in that they require lock-out of the whole system during the cleaning operation. Furthermore, manual methods have been found to be ineffective to thoroughly clean all the interior areas of a vessel due to inherent deficiencies of a manual operation and the difficulties encountered in reaching some areas because of the location of baffles, agitators, etc., in the vessels. There is the additional problem of subjecting the surfaces to be cleaned to scratches because of the use of scrapers.
Hand lances using high pressure nozzles have been used in the past but they create hazards for the operating personnel because of the high pressure involved.
It has been found that these and other difficulties can be overcome by using the method of the invention for cleaning enclosed vessels, for example, photographic vessels or kettles.